Telephone-exchange system



May 7,1929 H. HovLAND v TELEPHONE EXCHANGE SYSTEM Filed June 8, 1927 iwi. ,www l@ vlw n rTEIUHhUTIPmTI. m. Tm 1 w M .|n .Hmm M m. u f W, lmM A 0 Hw ....Tmz m. MTI m m. u N\ m W on W. A M mmf WT n+s|ultL |Vn|.|.||l|u m n A D W n b m 0 WM -vH Ulli mw@ m NUW. m# ...l VIII \4 lll mnmhnlnwlc m in, @MJ 5mn Ml M wm E u1u.. 1 mg SW L m u J w wh A E J/f A EQ ,T w11 @Ms .M r w w 95%@ Q Q www M HH l .Suo S m5 NN .zsm @w 5% j @w p Ulu W n .il w1 Q wl IQMM. Y @bien %\\^n1 w: 4@ BQ n F r wn L A N%\\WH 1.1% W Q@ 1| %%\L HT. Ulllllll l MEW @Qu N |u\ ,.Ul..

Patented May 7, i929.

' g einen UNlTED STA'll'l Pnlllil'l GFFHCE..

HENRY HOVLAIID,` F FLUSl-NGQNEVT YDRK, l BELL TELEPHONE lLABO- BATORIES, BTCOREOBITED, OF NEVI' YORK, l. Y., A CORGEATION 0F NEW YORK.

TELEPHNE-EXC-IANGE SYS'EM. l

4application filed. June S, 102'?.

This invention relates o automatic telcplioncexchanges and has ior its object the improvement oi line fin-der switches.

According to this invention the availability of lines to a group of linder switches is increased by causing said switches, when restored to their released positions, to move by relatively dii-tering amounts to assume their normal positions,

A 'feature oit the invention is a iinder switch which moves forward to find certain groups oi lines and which lindsy vother groups by moving to its extreme iorvmrdv position, releasing and again moving forward.

Another feature is a finder which inr one instance restores to normal by merely re leasing to the beginning of its line finding movement and inother cases byiirsti'estoi ing to its fully released position and then advancing to its normal position.

the invention is illustrated in a system ,4b. t 1' ed. ,'tl'n i using step y s ep ine iin ei siii cies cacaL having capacity for 200 lines.

ln the drawing, Fig. 1 illustrates in schematic manner a plurality oi these finder switches showing the normal positions of the brushes. The lines 204 appearvin two 100-point banks in the Yfinder switches and are multiplied, without any slipping arrangement, to a number of finders. Thebrushes oli the finder switch 200, for instance, normally stand in operative relation to the iirst level otterminals in their respective banks. The brushes of the next switch l201 normally stand in operative relation to the second level of terminals. The brushes of the third switch 202 stand opposite the third level and so on, the brushes oi the last switch 203 standing opposite the 10th level of Jterminals. By arranging each switch with a different normal position the hunting time is siilhciently reduced to allowy a straight multiple of the lines thus eliminating the expedient of slipping the lines from one switch to'another.

Figs. 2 and 3 show the details of a line -finder F. Switch F has two sets oi line brushes 106 and 107, each cooperating respectively with banks oit terminals 103 and 104:. rlhe switch also has a set of test brushes 108 coacting with the test bank 105. ln addif tion the :linder is equipped with two sets of. commutator segments 109 and 110 over which Serial No. 197252* appearing inthe bank 103. Likewise the subscribers line B appears in the corresponding level oft the other bank 104. It will be assumed that the brushes of the linder F iiormally stand opposite the 47th level of terminals in the banks 109, 10i and 105. Accordingly the'commutatoi brushes 111 `and l112 normally engage the 7th segments in the commutator strips 109 and 110.

Whenever a finder is taken in use to lind a line in its normal groupno vertical movement is necessary. The switch merely rotates into the level to 5nd the calling line'. ll a iinder is taken in iise to find a line occurring in a level above its normal level the switch lirst steps to iind the callinglevel and then rotates to seize the callingline. It a iinder is taken to ind a line located in a level below than its normal level, the magnet 118'is iirst operated to restore the shaft to its normal rotary position. Thereupon the .switch is stepped vertically to the top of the bank, in`

which position' the verticalholding pawl is withdrawn from the ratchet `and the switch drops to its i'ully released position at the bot, tom of the bank. When lthe shai'ft reaches the bottom of the bank the vertical holding dog againiengages the ratchet and the switch thereupon steps up to its normal level.

Fig. 3 shows a detail ot the shaft 300. Vih'en the shaft 300 reaches its uppermost position the vertical holding pawl301 is mechanically withdrawn from the ratchet permitting the shaft to drop. rllhe dog 301 is held out of engagement with the ratchet by the latch lever 30'? nntil the shaft reaches itsl lowermost position.

A. detailed description will now be giveinl.

assuming that the subscriber of line A initiates the call. The initiation of the call results inthe operation of the line relay 101 in.

an obvious circuit. Relay 101l operates the group relay 102. The group' relay 102` re,-

moves groundlpotential from the commutator segment 125.- Relay 102 also closes the start circuit 126 to initiate the movement of theY line finder` F. The start circuit 1n ayl be tracedlromgroumhcontact oi relay 102, conductor 126, normal contacts of relays 117 and 116, winding of slow release relay 119 to battery. Relay 119 operates and closes a circuit for slow release relay 116. The circuit torrelay 116 leads troni battery through its winding, outerfright ContactA oli relay 119, normal; con*- taet oit relay 117-' to the-grounded' start wire 126. Relay r116 locks in-a circuit: from battery through its windingV andS middle right front contact to the start wire'126as'traced; Relay 1-16 opens thecircuit` of relay 119and the latter relay releases.-

The rotary stepping11nagnet121 is now operated to stepthefhr-ushes over the terminals ofi the normal leveltov search for the calling line-Al-. The operating-circuit ofthe magnet 121; may lie-traced from batterytlirougli its' winding, letzbaclr contact o'relay 119, outer right front'contacty ot'relay- 116, lower contactsoifthe-combination 123, backcontact ot relay, 114,.inner left back `contact of' relay 119; conductor'127, to' groundat the outer right back contact'o relay117l The magnet 121 steps the brushes 106, 107*and108 to the iirst` set of* terminals. MagnetY 121 in operating"cl`oses an; obvious circuit for relay 114". Relay-114 operates andreleases the magnet 121. Magnet 121 in turn releases relay 114 which recl'oses the operating circuit of" the magnet; The switch operates in'this `manner until thecalling'line is reached;

lVhen'the lower testl brush 108 engages-theV test terminal ot the'calling line, a. circuit` is closed from battery through the winding of the cutofff'relay 100, Contact of` relay 101, conductor 129, lower brush.108,' upper winding of relay 115, outer lett back contact o'f'relay 117, lett; winding offrelay 114, conductor 130, outer leftcontactfof relay 116'to ground. Re-

lay 115,- which is a-rrangedto close its inner lower contact before any of its -other contacts are operated',` locls in a circuit tronrbattery through. its lower winding and contactv to ground at@ the Contact of' relay 116. Relay 115 extends .the calling line A over the tip and ring conductors of' the. trunk 124`to the line relay associated with a first, selector switch, not shown. In the nfelllrnown manner the lirst selector 4switch applies ground potential to the sleeve conductor, 130'to hold theswitch after the relay 1.16 releases, which itwilldo presently.

The test circuit abovel traced, leading through the left winding of relay/'114, maintains'this relay operated to prevent further stepping'ofthe switch by the rotary magnet 121. After relay 115. operates the test circuit isshiited and may nowbe trace.cl"from battery through'.v the cutoff relay 100 thence through the lower brush 108, upper front-contactrof relay 115, normalicontactf oi.I relay 113, left winding ot relay 114i to the grounded sleeveconductor 130. The culolil relay operates releasing the relays 101. andr 102. Relay 102.' releases relay 116. Relay 116 closes a circuit for the relay 117 traceable from battery through the right winding otra lay117, lower i'ront contact oit relay 115, inner left contact of' relay 116, contacts 122 to ground. from battery through its windingand its contact over'the lowerbrush 108, upper front contact of' relay 115, normal contact'of relay 1115, outer left front'. contact of relay 117, to the sleeve conductor 130. Relay 114 is shuntedand releases.'` V

The line finder is now ready.` for the conversation toI take place as soon as the connection is completed by succeeding switches. The circuit from the calling line A; extends over the back contacts of' relayv 113'and the trent contacts, or relay to the tipy and ring `conductors of the trunk 124.

At the end otconversatiomthe subscribers replace their receivers and ground'potential is removed from conductor 130;, Relay 115 releases and closes a circuit l'or the release n'lagnet- 118 from battery through the winding of the magnet, lower back contactoii relay 115, inner lett contact otrelay 116, to ground througlrthe springs 122. The magnet 118 withdraws the rotaryv holding pawl and the switch shaft restores toits normal rotary position. The springs 1221areV opened and the magnet 1&18deenergizes. The springs 122. also open the. circuit otrelay 117.. The switch is now initsnormalposition:with the brushes 106, 1`07fand108 standing, opposite the 7th level'oia terminals in the bank..

It will nextbe assumed that. the finder Fis taken iniuse to seize a calling. line in some level other thanits normali level. For eX,- ample, assumey the callingline appears inthe third'level. The initiationolilthe callfplaces aground potential on the incoming startwire Relay 100 is now held in a circuit l 132 originating `in theA callingy group.; This causes the operationot'relay 119 in amanner described. Relay 119 locks ina circuit. from battery. througliits winding and? innerV right contact, brusli.112,segment-.125. to ground.

the contact of.y group relay. 102. Relay 119 operates the relay. 116 in the manner above described and.. relay` 11.6V locksV independent-ly ol'` the contactofrelay 11a.

llhe switch is now stepped'by themagne: 120'to search for the calling. level of. lines.

The circuit for the magnet` 120 l'ea'ds from battery to the winding, thereof, outer left front contact ofrelay,119,.outerrightcontact ol relay 116, lower contact 12,3",.contact ofrelay- 114, inner. letj front Contact. of relay. 119, brush 112, terminal to groundat thencontact of' relay 102. Itwillfbe,noted'that relay.

102 is deenergized'sincetliis group has'not initiated' a call.`

The magnet 120' sets theV rotary movement.

shaft up one step and closes an obviouscircuit for relay 114. Relay 114 opens the circuit o1 the magnet which releases and in turn opens the circuit of relay 114. If the group opposite which the brushes are now standing through its winding and inner right and inner left contacts, contact of relay 114 to ground through the upper contacts 123. As the brush shaft reaches its lowermost position the upper contacts 123 are opened and the lower contacts again closed. kIf the first and second levels contain no calling lines, the correspond ing commutator segments 110 are grounded and relay 119 remains energized to close the operating circuit from magnet 120. Since it was assumed that the calling line appears in the third level, the brush 112, on reaching this level finds the segment ung'rounded. This permits the release of relay 119 vwhich opens the circuit of the stepping magnet 120.

The rotary magnet 121 operates to advance the brushes of the finder switch over the third level of lines to search for the calling line. Then the line is found the rotary movement ceases and the calling line is extended through to the first selector in the manner hereinbefore described.

'Io release the finder F from the third level of contacts, the release magnet 118 is firstv energized in the manner above explained to restore the. brushes to the beginning of their It will be noted that the segments of the commutator 109 are all connected to the conductor 133 with the exception of the normal position. segment. Accordingly the brush 111 applies ground potential to the conductor 133 in all positions other than the normal position of the finder. T he grounded conductor 133 extends to the inner right contact of relay 116 and the right winding of relay 117 holding the relay 117 operated after the rotary contacts 122 have restored to the position shown. The stepping magnet 120 is again energized in a circuit from battery through its winding, inner right contact of relay v117, lower contacts 123, contact of relay 114, inner left back contact of relay 119, conductor 127, outer right front contact of relay 117, closed contacts of the spring combination 122 kto the grounded conductor'133. The magnet 120 operates in this circuit toy step the finder switch up to its normal position where ground is 'removed from conductor 133 to pre-vent further stepping of the switch and to release relay 117.

Should the calling line occur in the other group of 100 lines the switch operates in substantially the manner described except that .the brushes 107 are used and both relays 113 and 115 are operated. The test circuit for a line in this group may be traced from the upper brush 108, upper winding of relay 113, upper back contact of relay 11.5, normal contact of relay 113, left winding of relay 114 to the ground conductor 130. Relay 113, which is arranged to close its inner lower contact Vbefore any of its other contacts operate, locks to ground through the spring combination 122. Relay 113 closes an operating circuit from battery to the lower winding of relay 115, upper middle contact of relay 113 to the grounded conductor 130. The tip and ring conductors of the calling line, such as the line B. are thus extended over brushes 107 through the front contacts of relays 113 and 115 to the corresponding conductors ofthe trunk 124-. f

For a further description of line finder switches of the general type illustrated in this disclosure, reference is made to the patent to Carpenter' No. 1,567,240, granted December 29, 1925.

While the invention'has been disclosed in connection with finders of the 20G-point typeit is obvious that it may switches of other types.

What is claimed is 1. In a telephone system, lines arranged in groups, automatic switches for making connection with said lines, means for releasing the switches to the same position relative. to said groups of lines, and means for setting said switches in different normal positions with respect to said groups.

2. In a telephone system,.finder switches, lines appearing in groups in said finders, means for releasing said finders after use to the same position relative to said groups of lines, and meansV for advancing said finders to different normal positions with respect to said groups.

3. In combination, finder switches, telephone lines appearing in said kswitches in groups, means for releasing each finder to the same position as the other finders relative to said groups,and means for setting each finder in a normal position which differs from the normal positions of the remaining finders relative to said groups. l f

4. In a telephone system, finders, each having a brush set, lines appearing in levels in said finders, means for releasing all brush sets to the same level, and means for setting be embodied in said brush sets in normal positions each in operative relation lto a different level.

5.v In .a telephone system,y automatic switches, lines appearing in levels in said switches, abrusli for each-switch, means tor releasing all brushes to a posit-ion adjacent.

the brush set inra plurality ot movements to seize airline-in another' ot'saidlevels.

7.,[n combination, an automatic switch,

' lines appearing in levels in said switch, a

brush set for the switch normally standing oppositea givenlevel, means for voperating said brush set-1 to seize. a line in saidA given level, andi means forV operating theA brush set to seize a linein any other level whether above or below said given level.

8. Incombination, an automatic switch, lines'appeaningi in levels in said switch, a brush iiortheswitch normally standing opposite a given level, means for rotating said brush; toiseize* a lineiny saidy given level, and means for mov-ing;l thei brush vertically and thenrotatingfit toseizeaeliiieinv a level above said given level;v

9. In combination, an automatic switch, lines1 appearing in levels in said switch, a brush forithe switch normally' standing opposite a given level, means for rotating said brush topseize a line in saidrgivenl'evel, means for moving the brush vertically to a given position, means tor releasing said-brushto its extreme lower position, and means `for causing saidbriish to move vertically and to rotateto seize aline in a level below said given level.

1.0. In combination, an automatic switch,

lines appearing in levels in said switch, a

brush i'ior` the switch normally standing. opy l1. ln combination, a iind'er switch, lines appearing.inlevels in said-switch, a brush for the i'indeiswitch normally standingv opposite af given level, ineensitor rotating said brush to seize alinefinthe given level,vineans for moving said brush vertically and rotating it to seize ai line in any other level, means for releasing-the brush from the givenlevel by, a rotary movement only, and means for reieas ing the brush from any otherlevel by restoring it in a rotary movement,lrestoring. it to its-fully released verticalposition and advancing'it in a-verticalmoveincnt to its nornial'position.Y f

ln witness whereof, l hereunto subscribe my name this .lt-h clay ot"`J`iine, A. D. 1927.

' HENRY HOVLAND, 

